In the early part of the nineteenth century John Dalton (1766-1844), a British chemist-physicist, firmly established the atomic theory of matter. He was born on September 6, 1786, in Eaglesfield, England. His father was a hand-loom weaver. He was educated at the village school on a scholarship from a fellow Quaker until age 11. At age 12, he began teaching at the local school. In 1781, he moved to Kendal to teach at a school there. Then in 1793 Dalton moved to Manchester, where he remained the rest of his life. In Manchester, he taught at the Presbyterian institute, Manchester New College.
Dalton is famous for a variety of discoveries, but it was his development of atomic theory that was his most important contribution. In his experiments on the solubility of gases in water, he found that the expected same solubility didn't exist. Dalton developed the theory that atoms of different gases had different weights. His atomic theory was first stated in its entirety in a lecture at a Royal Institution lecture in 1802. Although some of his calculations proved to be incorrect, his system on atomic weights was on the right track. His theory remained unconfirmed until more than a decade after his death on July 27, 1844, in Manchester.